Regenerative hot-blast stove



(Nb Model.) I H. A. LAUGHLIN.

REGBNERATIVE HOT BLAST STOVE. I 13 0. 355,181. I Patented Dec. 28, 1886.

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UNITED STATES PATENT Erica.

HENRY A. LAUGHLIN, OF PITTSBURG, PENNSYLVANIA.

REGENQERATIVE HOT-BLAST STOVE.

- SPECIFICATION forming part of Letters Patent No.355,181, dated December 28, 1886.

Application filed January 20,1886. Serial No. 189,142. (No model.)

To aZZ whom it may concermv Be it known that I, HENRY A. LAUGHLIN, a citizen of the United States, residing at Pitts burg, in the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvements in Regenerative Hot-Blast Stoves, of which improvements the following is a specification.

In the accompanying drawings,which make part of this specification, Figure l is a vertical central section through a hot-blast stove em-. bodying my invention, at the line 00 :10 of Fig. 3; Fig. 2, aplan or top view of the same; Fig. 3, a horizontal section at the line yyof Fig. 1; Fig. 4, a similar section at the line 2 z of Fig. 5; Fig. 5, avertical section at the line w w of Fig. 4, and Fig. 6 a similar sectionlon an enlarged scale.

My invention relates to stoves or ovens for heating the blast of air supplied to blast-furnaces, of the class or type known as regenerative hot-blast stoves, in which the products of combustion of the waste gases from the furnace are passed through a series of fire-brick channels, fines, orpassages, to which they impart their heat, which is subsequently given off to the blast,which is forced in reverse direction through such heated passages in its traverse to the tuyeres of the furnace. Hotblast stoves of such type, as heretofore constructed, have been subject to the objection of being costly in construction and maintenance, owing to the character of the arrangements adopted for the introduction and discharge of the gases and air and the application of heat to the latter, and owing to the fact that a material difference of temperature exists within the stoves between that portion of their bodies in which the combustion of the gases takes place and that which contains the regenerative surfaces proper, such difference inducing an unequal expansion and contraction,which rapidly displaces and destroys the brick-work, and renders frequent and expensive repairs necessary. A further objection is found in the tendency of the fines or checker-work to clog by accumulation of dust carried in by the furnace-gases, unless the passages through the same are made of unduly large capacity, and in the difficulty and delay experienced in the removal of such deposits.

The objects of my invention are to simplify and economize the construction and maintenance of regenerative hot-blast stoves, to distribute the area of regenerative heating-surface uniformly throughout the interior of the stove, and to increase the area of such surface practicable for given capacities, and to afford convenient and ample facilities for effectively cleaning out and removing deposits of dust from time to time, as required.

To these ends my invention, generally stated, consists in a hot-blast stove having a series of vertical regenerative fines or passages, disposed uniformly throughout its transverse section, and divided into two or more lengths ,by a horizontal cleaning passage or passages, an external uptake combustionchamber leading intoa dome or upper chamber communicating with all of said flues at their upper ends, and a lower chamber communicating with the lower ends of said fines, and with suitable delivery and discharge pipes.

The improvements claimed are hereinafter fully set forth.

In the practice of my invention the body or shell 1 of the stove is composed of fire-brick or other refractory material, built up into a vertical cylinder of any desired height and diameter,in accordance with the required duty, and inclosed in a tight casing of iron plates in the ordinary manner. One or more substantial continuous vertical walls, 2, of fire-brick, (three being shown in the present instance,) are built entirely across the interior of the shell, said walls forming divisions or partitions between a series of vertical regenerative fines, 3, and extending continuouslyfrom the bottom of the stove to a dome or cylindrical upper chamber, 4, which covers the top of the same and communicates with the upper ends of all the vertical fiues 3. A series of cross vertical walls, 5, of fire-brick, intersects at right angles the continuous Walls 2. Said walls 5, which subdivide the space between the walls 2 and be- 9 5 tween saidwallsand theshell 1,formendboundaries of the fiues 3, extending from arches 6, sprung over a lower chamber, 7 ,which extends entirely across theshell and communicates with eachof the fines 3 at its lower end,-to the dome loo or upper chamber, 4.- It will thus be seen that the space within the shell or body of the stove, between its upper and lower chambers, is wholly occupied by regenerative heating:

surface, which is disposed as uniformly as may be throughout its entire transverse section, the largest practicable area of heating-surface being thus attained, the same being greater or less, as may be desired, in accordance with the numberof walls employed, and being subject to substantially uniform temperature throughout. a

In order to enable deposits of dust from the furnace-gases which may accumulate in the fines 3 to be readily and thoroughly cleaned out and removed, as may become necessary from time to time, each of the crosswalls 5, separating said flucs,is intersected horizontally by one or more transverse cleaning channels or passages, S, of sufficient height and width to admit of the entrance of a man, said passages being in line horizontally and forming, with the flues 3, clear transverse openings extending entirely across the shell. An opening, 9, closed by a door, 10, is formed in the shell at one end of each of the transverse passages formed by a series of fines, 3, and cleaning channels 8, the doors being accessible from platforms 1], on the outside of the shell, and separated one from another by the continuous wall 2 at the level of each series of cleaningpassages. An opening, 12, which'is closed by a door, 13, is formed in the dome 4, to afford access to the upper ends of the top lengths of flues. It will be seen that the comparatively short lengths of flues intervening between the several series of cleaning-channels and between said channels aud the dome and lower chamber, respectively, may be easily and thoroughly brushed and scraped out by a man workingin the dome and in the several channels successively.

The combustion of the furnace gases by which the stove is heated is effected in a vertical uptake combustion-chamber, 14, of fire brick suitably cased with iron plates, said chamber being wholly exterior tothe stove and extending from a foundation at or adjacent to the level of the base thereof to the dome or-upper chamber, 4, into which it opens at its upper end. A gas-supply pipe, 15, leading from the downcomer or gas-discharge pipe of the blast-furnace, and provided with a proper valve or gate, 16, opens into the combustion-chamber 14, near its lower end, and a blast-delivery pipe, 17, having a valve, 18, leads from the lower end of the chamber 14 to the tuyeres of the furnace. Air for supporting combustion is admitted to the chamber 14 through a lower opening, 19, governed by a valve or door, 20. Ablast-supply pipe, 21, having a valve, 22, leads from the blowingcylinder into the lower chamber, 7, of the stove, and a waste-gas pipe, 23, governed by a chimney-valve, 24, leads from said chamber to a discharge-flue or chimney. Access to the lower chamber, 7, may be had, when desired, through an opening, 25, therein,which is closed bya door, 26. It will be seen that as the combustion-chamber 14 is exterior to the shell and regenerative portion proper of the stove, the higher temperature prevailing in the former during the combustion of the gases intake combustion chamber 14, at its lower end,

and is ignited and maintained in combustion therein and in the dome 4, a proper supply of air to support combustion being admitted through the opening 19. The chamber 14 and dome 4 are thereby raised to a high degree of heat, and the products of combustion pass downward through the vertical flues 3, highly heating the same in their traverse, and are collected in the bottom chamber, 7, from which they pass off through the waste-gas pipe 23 to the chimney. After the gas has been burned sufficiently long to thoroughly heat the chambers and flues the gas-valves 16 and 24 are closed and the air supply and delivery valves 22 and 18- opened. The blast from the blowing engine enters the lower chamber, 7, and passes upwardly therefrom through the series of heated fines 3 into the dome 4, and thence downwardly through the chamber 14 and is thoroughly heated in its traverse to the air-delivery pipe, 17 through which it passes to the tuyeres of the furnace.

Two or more stoves being combined in one plant, the operations of heating the regenerative surfaces by the combustion of the gas and of absorbing the heat evolved therefrom by a current of cold-blast are alternately conducted, and in the installation of such aplant one or more stoves additional to the two which are necessary for such alternate operation should be provided, so that a spare stove may always be in condition of operation during the periods required for cooling and cleaning out each of those which are otherwise in continuous operation.

I- am aware that a hot-blast stove having a vertical uptake or combustion-chamber located exterior to its shell was known prior to my invention, and such therefore I disclaim.

I am further aware that hot-blast stoves have been proposed which embody a series of re generators located one above another and separated by combustion-chambers occupying the entire transverse section of the stove. Such structure, which I likewise disclaim, differs from my invention in the absence of continuous vertical walls and of cross-walls provided with openings, which construction,while imparting substantial strength and support to the entire series of regenerative fines, enables convenient access to be had at intervals to their interior for the removal of dust therefrom, so that such accumulation of foreign IIO matter in the flues as would impair their normal operation may be effectively prevented.

I claim herein as my invention- 7 1. In aregenerative hot-blast stove, the combination of a shell or body having an upper dome and a lower collecting and distributing chamber,- a series of vertical regenerative-fines extending between said dome and chamber, and a series of cleaning channels or passages separated by continuous vertical walls, each transverse row of said passages communicating in line horizontally with an opening in the l shell and with a transverse row of the regensaid cross-walls at different levels and in rows in line horizontally with openings in the shell and constituting transverse cleaningpassages leading into each of the vertical flues, substantially as set forth.

In testimony whereof I have hereunto set my hand.

, HENRY A. LAUGHLIN.

Witnesses:

J. SNOWDEN BELL, R. H. WHITTLEsEY. 

